1. Field of the Invention
The present invention relates to a fluorescence detection system, which detects fluorescence in a microfluidic chip having a microchamber and measures the amount of the fluorescence. In addition, the present invention relates to a method for detecting fluorescence in microfluidic chip having a microchamber and measuring the amount of the fluorescence.
In the fluorescence detection system of the present invention, an optical device detects fluorescence generated by a fluorescent material. The position of the outer circumference of a microfluidic chip is identified based on the amount of the detected fluorescence. Then, the position of a microchannel is calculated based on the position of the outer circumference of the microfluidic chip and the distance between the outer circumference and the microchamber. Hence, the amount of the fluorescence only generated from the microchamber of the microfluidic chip is automatically calculated. Further, a plurality of samples can be analyzed at the same time, thereby reducing analysis time and cost.
2. Description of the Related Art
A microfluidic chip is fabricated by forming microchannels on a first substrate by micromachining such as photolithography, hot embossing and molding, and bonding a second substrate on the first substrate. Therefore, so that a very small amount of fluid can be contained and controlled in the chip. The advantage of this microfluidic chip is that the amount of reagent to be spent and analysis time can be reduced.
A microchamber in the microfluidic chip is a space that stores a material to be detected, which is introduced through an inlet and a microchannel. The width of the microchamber is larger than or equal to that of the microchannel. The width of the microchannel is usually several tens or hundreds of micrometers.
Fluorescence detection in the microchamber can be adopted in monitoring biochemical reactions such as Polymerase Chain Reaction (PCR), enzyme reaction or immunity analysis, in which the amount of fluorescence changes.
In PCR, denaturation, annealing and extension are performed at different temperatures, and such a temperature cycle can be iteratively conducted to amplify DNA.
There are several methods for monitoring the PCR process in real-time, most of which adopt the fluorescence detection at present.
Various methods have been introduced for the fluorescence detection. In one example, a dye such as SYBR Green I is bonded to double helix DNA, created by PCR, in order to enhance fluorescence. Another example is TaqMan® method, In this method, a DNA sequence capable of being bound between two primers is used as a probe except for primers which are used in PCR, and a fluorophore and a quencher are bound to both ends of the probe.
When cutting the probe using exonuclease activity of Taq polymerase used in DNA synthesis, the DNA bound between the fluorophore and the quencher is cut, and thus, the bond between the fluorophore and the quencher is broken. At this time, the emitted fluorescence is analyzed.
However, there are problems in that apparatuses used in the fluorescence detection should be precisely operated to obtain correct results.